The Geo-Informatics and Space Technology Development Agency (GISTDA) has warned that Bangkok and its neighbouring provinces, Pathum Thani and Nonthaburi, face heightened flood risks following the Royal Irrigation Department’s decision to increase water discharge from the Chao Phraya Barrage in Chai Nat.
The department raised the release rate from 2,750 to 2,800 cubic metres per second on Sunday after heavy inflows from northern rivers, fuelled by the remnants of former Storm Kalmaegi, surged downstream.
According to GISTDA, the increased discharge has pushed water levels higher along the Chao Phraya River and its tributaries, raising the chance of overflow in riverside zones.
High sea tides are also compounding the problem, making it more difficult to drain water from the capital and its surrounding provinces during this period.
Low-lying areas outside flood barriers, known as “missing-teeth zones”, remain the most at risk. GISTDA’s latest satellite map highlights orange zones that could flood at discharge rates of 2,700 cubic metres per second, while red zones mark areas that would be affected if the rate stays at 2,800 cubic metres per second.
In Pathum Thani, flood-prone zones stretch along both sides of the Chao Phraya River from Sam Khok to Muang district.
In Nonthaburi, the most vulnerable areas are in Pak Kret and Bang Kruai districts.
In Bangkok, riverside communities in Bang Phlat, Bangkok Noi, Bangkok Yai and Thon Buri have been urged to stay alert and monitor updates closely.
Most of these high-risk areas are located outside the city’s flood barriers, GISTDA noted. Authorities are keeping a close watch and advising residents near the river, particularly those in orange and red zones, to move belongings to higher ground and follow updates from official channels.
GISTDA said it continues to monitor the situation via satellite imagery to assist agencies in planning mitigation measures and ensuring a swift, coordinated response.
